Department of Applied Mathematics and Theoretical Physics, University of Cambridge, UK

May 21, 2013

Atlas 2: package na diferenciální geometrii pro Mathematicu

Jakub Haláček

ITP

(seminar in Czech language)

May 28, 2013

On the completeness of impulsive gravitational wave spacetimes

Clemens Sämann

DIANA, Faculty of Mathematics, University of Vienna

After briefly discussing the non-impulsive (smooth) case, we will show that every impulsive wave-type spacetime of the form $M=N\times R^2_1$, with line element $ds^2 = dh^2 + 2 du dv + f(x)\delta(u) du^2$ is geodesically complete. Here $(N,h)$ is an arbitrary connected, complete Riemannian manifold, $f$ is a smooth function and $\delta$ denotes the Dirac distribution on the hypersurface $u=0$. Moreover the geodesics behave as is physically expected.

July 10, 2013

POZOR! Posunuto na středu (od 13:10)!!!

Dark universe and marvels of gravity: exploring the idea of a geometric interpretation of the dark phenomenology

Dr. Sante Carloni

ESA Advanced Concepts Team, ESTEC, Noordwijk, The Netherlands

In this talk I will present the idea of a geometrical interpretation of dark phenomena on cosmological and astrophysical scales. In particular, I will review the status of our knowledge on the physics of extensions of General Relativity in relation with dark matter and dark energy and I will delineate the new challenges in this research field for the next years.